"To be applicable to such a wide range of libraries, it is necessary that the standards not be prescriptive. Instead, they provide a comprehensive outline to methodically examine and analyze all library operations, services, and outcomes in the context of accreditation. The expectation is that these standards embrace key principles that will continue to be espoused by regional accrediting associations as critical elements or core requirements that provide a foundation upon which a library documents its compliance." (preamble to the "Standards for Libraries in Higher Education")
The current general standard, Standards for Libraries in Higher Education, is designed to guide academic libraries in advancing and sustaining their role as partners in educating students, achieving their institutions’ missions, and positioning libraries as leaders in assessment and continuous improvement on their campuses.
The Association of College and Research Libraries (ACRL, a division of ALA), also has additional standards and guidelines on a variety of topics of interest to the academic and research communities including access, academic status, and information literacy.
"Instead of standards to be applied nationally, this publication describes a planning process to be used by individual communities. Through the planning process outlined [in this book], libraries will set up standards appropriate to the local conditions and needs; design strategies to reach them, and inaugurate a planning cycle which involves continuous monitoring of progress and regular adjustment of objectives as community conditions and needs change." (foreword of A Planning Process for Public Libraries)
For a fuller discussion of the shift from an inputs approach to an outcomes approach, see Goodrich, Jeanne. "Staffing Public Libraries: Are There Models or Best Practices?" Public Libraries 44, no.5 (Sep/Oct 2005): 277-281. (PDF: p.31 of the 64 page file), as well as the resources from the Public Library Association (PLA), a division of the American Library Association, on Performance Measurement.
Please note that individual states may have standards, guidelines, and laws for public library service. Some have been added to the knowledge base of the Chief Officers of State Library Agencies (COSLA), but it is best to consult the state library in your own state for guidance.
The National School Library Standards for Learners, School Librarians, and School Libraries, developed by he American Association of School Librarians (AASL), published by ALA Editions, reflect an evolution of AASL Standards. These standards are designed to empower leaders to transform teaching and learning. ,The standards and guidelines found in three previously separate publications—"AASL Standards for the 21st-Century Learner,” “Standards in Action,” and “Empowering Learners”—have been integrated, remodeled, and framed within a single text. Featuring a new streamlined AASL Standards Integrated Framework for learners, school librarians, and school libraries, these standards emphasize the importance of all three standards sets while ensuring that standards-related activities are mutually reinforcing.
The AASL Board adopted the Position Statement on Quantitative Standards on June 28, 2013, saying, in part, "Quantitative standards offer baseline numbers for everything from budgets to numbers of periodical subscriptions to square feet of shelving space. They provide a measure that allows comparisons for individual school libraries as well as a means to advocate for new resources. Minimal standards, however, are problematic because they can also be considered sufficient, or even “ideal,” with the unintended consequence of providing a ceiling rather than a floor for evaluating a school library program and justifying new resources. ... School librarians should engage in a continuous evaluation of the effectiveness of the school library program to meet the needs of patrons for access to ideas and information through the resources of the library."
There may also be state standards that apply; please consult the state department of education or state schoollibrary association, as appropriate.